The site was polluted by a UC Berkeley Field Station and a Zeneca sulfuric acid manufacturing center. Restoration is underway.[2] The marsh is so polluted that the San Francisco Bay Area Regional Water Quality Control Board named it a "toxic hot spot" and one of the "top 10 most polluted" sites in the Bay Area in 1998.[3] The contamination includes dangerous levels of toxic chemicals and organic compounds such as Arsenic, mercury, and PCBs.[3]